THE DEVELOPMENT OF RHESUS MONKEY (MACACA MULATTA) SOCIAL NETWORKS AS A TRANSLATIONAL MODEL FOR HUMAN PEER INTERACTION NETWORKS

A wealth of research shows that social networks can buffer against stress and promote health in humans. In childhood and adolescence peer relationships have a growing influence on behavior and health. We explored whether peer social networks in monkeys share similar features to human social network development to determine whether then can be used as a translational model to better understand how variation in social network positions impact health and fitness. We studied social interactions (e.g. play, proximity, contact) of 33 rhesus monkeys living in a single social group from birth to 3 years using 10 min focal sampling twice weekly. Peer social networks were constructed at three yearly intervals starting when subjects were 3-5 months of age, and we calculated measurements of network structure (e.g. density, centralization, clustering coefficient). Overall, peer interactions made up 20-23% of all social interactions (compared to 30% for human children). Peer-interactions networks show similar network structure from infancy to 1 year of age, however networks at 2 years of age show lower density, and greater centralization and clustering. Further investigation by behavior type shows that contact networks drive the increases in centralization and clustering while play and proximity networks appear to drive the reduced density. These results suggest that juvenile rhesus monkeys exhibit a similar pattern of increasing clustering and differentiation of social relationships in adolescence as humans do.